1. Field of the Invention
Implementations of various technologies described herein generally relate to methods and systems for glacial geomorphologic mapping.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.
Geomorphology is a science of landforms that studies the evolution of the earth's surface and interprets landforms as records of geological history. More specifically, glacial geomorphology studies the evolution of the earth's surface as shaped by glaciers. Glacial geomorphology is useful for the exploration of natural resources of the arctic regions. Typically, the geomorphologic interpretation of glacial features uses surface geologic mapping validated by satellite imagery.
Moraines are glacial features that may be of particular interest in glacial geomorphology. The term, moraine, refers to any glacially formed accumulation of unconsolidated glacial debris, such as, soil and rock. The debris may occur in currently and formerly glaciated regions. This debris may have been plucked off the valley floor or fallen off of valley walls as a glacier advanced. Moraines may be composed of debris ranging in size from a silt-like material called glacial flour, to large boulders. Moraines may be located on the glacier's surface or deposited where the glacier has melted.
Different types of moraines include lateral moraines, ground moraines, and terminal moraines. Lateral moraines are parallel ridges of debris deposited along the sides of a glacier. The debris is deposited on top of the glacier by frost shattering of the valley walls and from tributary streams flowing into the valley. The till is carried along the glacial boundary until the glacier melts. Because lateral moraines are deposited on top of the glacier, they do not experience the post-glacial erosion of the valley floor and therefore, as the glacier melts, lateral moraines are usually preserved as high ridges.
Ground moraines are till-covered areas with irregular topography and no ridges. Ground moraines often form gently rolling hills or plains. The debris of ground moraines may be deposited as the glacier retreats. The ground moraine is typically located between the two lateral moraines.
Terminal moraines are ridges of unconsolidated debris deposited at the terminus, or end of the glacier. Typically, terminal moraines reflect the shape of the glacier's terminus. Glaciers act much like a conveyor belt carrying debris from the top of the glacier to the bottom, where the debris is deposited in terminal moraines. The longer the terminus of the glacier stays in one place, the more accumulation there will be. Terminal moraines typically mark the maximum advance of the glacier.